Pulp-grinding machine.



No. 696,225. Patented out. 3|. |899. H. .1. FmK.

PULP GRINDING MACHINE.

(Application med my 5, 1599.)

(No Model.)

Inpen for.

m tnesses). Jmzef/J UNITED STATES PATENT @Ei-fion.

HERBERT JQ FRINK, OF HOLYOKE, MASSACHUSETTS.

PU LP-G RINDING MACHINE.A

SPECIFICATION forming partof Letters Patent No. 636,225, dated October 31, 1899.

Application filed .Tuly 5, 1899. Serial No. 722.798. (No model.)

To @ZZ whom t may con/ceri.-

Be it known that I, HERBERT J. FRINK, of Holyoke, county of Hampden, State of Massachusetts, have invented an Improvement in Pulp-Grinding Machines, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention relates especially to apparatus for grinding Wood-pulp and the like; and it has for its object more particularly the production of novel means for guiding or directing the piston-rods which operate the pressure devices employed to force the material to be ground against the grinder.

Wood -pulp grinders usually comprise a curb or case covering the grinding stone above suitable bed-plates, and the wood-boxes are firmly secured to the case. A hydraulic cylinder is bolted to each wood-box and is usually made of cast-iron lined with brass or bronze, a suitable piston having an attached piston-rod provided at its inner end with a follower or presser, which acts upon and forces the wood in the wood-box against the grinder. It is the usual practice to extend the piston-rod through suitable stuffing-boxes, one at each end of the cylinder, a gland of brass or bronze being fastened in the stuffingbox by tap-bolts or otherwise, a-nd in practice such construction has been found very objectionable owing to the friction on the piston-rod caused by the unequal bearings therel for provided by the two stuffing-boxes.

` The men employed to tend wood-pulp grinders are not skilled mechanics, and when a stuffing-box leaks the attendant is very apt to tighten it up until the leakage is overcome, without paying much heed to the alinement or proper setting of the bearing, and as a consequence a large proportion of the power ap- .plied in the cylinder is lost in friction and the output of the grinder correspondingly lessened.

If the upper extension of the piston-rod is not used, it is practically impossible to guide the follower with accuracy and there is more or less side movement of the follower, due to the variation in the sizes of the sticks of wood, and the piston and cylinder are worn .unequally By my invention I provide an upper bearing or guide for the piston-rod extension, which maintains the latter in proper alinement, while obviating the tight fit and consequent friction resulting from the use ofa stuffing-box at each end of the cylinder.

Figure l in side elevation represents a sufiicient portion of a grinding-machine to be understood, with one embodiment of my invention applied thereto, the valve-chests and couneotions being omitted from the drawings for the sake of clearness. Fig. 2 is an enlarged diametral sectional view of one of the pressure-cylinders, taken at the upper end thereof to more clearly illustrate myinvention. Fig. 3 is an end view of the guide or bearing forming a part of my invention, and Fig. 4 is a sideelevation thereof.

Referring to Fig. l, the grinding-stone Gr, curb or casing C, covering the grinder above the bed-plate B, the open-ended Wood-boxes A, mounted on the curb, and the cylinders D, secured to the tops of the Wood-boxes in any suitable manner, may-be and are of usual construction well known in this type of appa--Y ratus. The piston P in each cylinder and of usual construction has rigidly secured to it a piston-rod P', extended through a stuffingbox b (see dotted lines, Fig. l) at the inner end of the cylinder, anda follower PX is mounted on the end of the rod extended into the Wood-box A to force the wood against the grinder. The upper cylinder-head D (see Fig. 2) is provided with a central hub or boss D2, through which is loosely extended the piston-rod extension P2, there being an ample clearance cZX between the opening in the innerend of the hub and the piston-rod extension. A guide and bearing for said extension is placed in the hub D2, said guide being shown separately in Figs. 3 and 4. as a bushing f, longitudinally ribbed exteriorly atf", the ribs extending beyond one end of the body portion f, and I prefer to make the guide of composition metal or bronze. The ribs f' snugly enter the hub D2 and hold the guide from lateral movement, the latter being maintained firmly in place by an elongated hood, shown as tubular and threaded into the hub at hX to bear against the outer end of the guide, the hood receiving the piston-rod extension P2 on its outerstroke and being shown IOO as closed Huid-tight bya screw-cap H. The bushing f thus acts as a bearing and guide for the piston -rod extension and tits only snugly enough for that purpose, the spaces between the ribs f forming channels f2, Fig. 3, which permit the free passage of the Huid contents of the cylinder into and out of the hood as the piston is moved in the cylinder. I am thus enabled t-o avoid all of the friction which would be caused by using the customary form of stuing-box, While accurately guiding and maintaining the piston-rod and its extension in perfect alinement and properly holding the follower to its work.

Having described in v invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In a pulp-grinder, a pressure-cylinder, its piston, a piston-rod having an extension loosely passed through the outer cylinderhead, a channeled guide-bearing mounted on the latter, for the rod extension, and a hood secured to the cylinder-head and maintaining the guide-bearing in place, the hood communicating With the cylinder through the channels of the guide and inclosing the exposed portion of the rod extension.

2. In a pulp-grinder, a pressure-cylinder having its outer head provided with a hollow boss, a guide therein and provided Withiiuidpassages, a closed hood mounted on the head and retaining the guide in place, a piston, and an extension-rod attached thereto, extended loosely through the boss and into the hood, the guide forming a bearing for and directing said extension-rod.

In testimony whereof I have signed my name to this specilication in the presence of two subscribing Witnesses.

HERBERT J. FRINK.

Witnesses:

SAMUEL RAYNOLDS, CHAs. A. CHASE. 

